940
FXUS65 KMSO 101944
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
144 PM MDT Thu Jul 10 2025

.DISCUSSION...

KEY MESSAGES:

- Warming trend Friday into the weekend, with moderate heat risk
  impacts across low elevations of central Idaho.

- Next system arrives Monday into Tuesday, with potential for
  backdoor cold front, northeast winds, and recreation impacts.

GOES Satellite and radar observations this afternoon show a upper
level disturbance moving across southern Alberta, with scattered
showers across northern portions of Lincoln and Flathead Counties.
Blustery westerly winds have began to surface, with gusts
expected to reach 25-30 mph across valley areas through this
evening across western Montana. Higher gusts near 40 mph have been
observed across high elevations along the divide in northwest
Montana, including Logan Pass in Glacier Park. Showers will
continue through this evening across northwest Montana, focusing
across Glacier Park, with enough moisture and instability being
present for a couple isolated thunderstorms.

A ridge of high pressure will amplify along the Pacific Northwest
coast Friday into the weekend. This will place the Northern
Rockies under a warm and dry west-northwest flow pattern.
Confidence is high for rising temperatures through the weekend,
with highs reaching into the upper-90s to low-100s across lower
elevations of central Idaho. These temperatures will stretch over
the weekend, leading to a moderate risk of heat impacts.
Temperatures will also run 10-15F above normal across western
Montana, with Sunday being the warmest day of the upcoming week.

Ensemble models continue to suggest a breakdown of the ridge
Monday into Tuesday next week as a trough drops southeastward from
British Columbia. Half of ensemble clusters bring a strong
backdoor cold front southward from Canada across the divide
Monday evening into Tuesday morning, with north-northeast winds
developing across western Montana. Guidance has trended towards
this solution, with previous ensemble runs showing a 20% chance
for this solution 12-24 hrs ago. Precipitation will generally
focus along the divide in northwest Montana under this scenario,
with probabilities for >0.10" of precipitation peaking at 50-60%
across Flathead County and the divide. The bottom line is those
with plans across the higher elevations and in Glacier Park
should monitor the forecast closely given the potential for
widespread precipitation, much colder temperatures, and north-
northeast winds making for adverse backcountry conditions for this
time of year. Furthermore, choppy lake conditions across Flathead
Lake would be a concern if this backdoor cold front solution
comes to fruition. We will monitor this system closely in the
coming days.


&&

.AVIATION...GOES Satellite imagery shows a cumulus field along and
north of the I-90 corridor associated with a passing disturbance
along the US-Canadian border. Scattered showers are seen on
regional radar imagery across Lincoln and Flathead County as of
10/1900Z. This activity will continue into the evening, with the
risk of lightning from isolated thunderstorms focusing east of
KGPI over Glacier National Park and the divide. Blustery westerly
winds of 20-25kts will continue through 11/0200-0400Z for valley
areas as this disturbance passes. Skies will clear overnight as
high pressure begins to build into the region.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&

$$